Most, if not all, intellectual traditions of ancient India were founded on a mūla text the authority of which was—at least nominally—considered unassailable. In the case of vyākaraṇa the cornerstone of the grammatical śāstra was the Aṣṭādhyāyī of Pāṇini, together with one of its earliest commentaries, the Mahābhāṣya of Patañjali that incorporates the vārttikas of Kātyāyana.

In time, the hierarchy of authoritativeness among the so-called three munis, the founding fathers, as it were, of Pāṇinian grammar, came to be reversed and greater authority was accorded to the latest author, Patañjali, followed by Kātyāyana and Pāṇini. This reversal, whether justified or not, is itself the manifestation of a sense if not of history, of evolution, the implicit acknowledgment that Pāṇini's grammar was perfectible, and consequently, that his first commentators had the task not simply of explaining it for the sake of men who were less quick-witted, but also of amending and supplementing it. Furthermore, this sense of evolution entails the recognition that the three munis may have and indeed had conflicting views on some issues, although all of them shared the basic principles laid out in the Aṣṭādhyāyī.

As a matter of fact, the Pāṇinian tradition is anything but mono lithic, although this is sometimes disregarded by contemporary scholarship, both ‘traditional’ and ‘Western’. But this impression of its unbroken continuity and general unanimity is, to a large extent, the result of the ways in which it came to represent and reproduce itself over the centuries and, especially, in medieval times.